The present invention relates to a woodworking planing or shaper head of the type commonly used to shape wooden components of furniture.
Shaper heads of the described type typically comprise a cylindrical base member having a plurality of cutting blades mounted in a spaced apart arrangement about the circumference thereof. The head is mounted for rotation about a vertical axis, and the workpieces to be cut are fed horizontally across a table and into contact with the rotating head, either manually or by an automatic feeder.
Various prior designs of shaper heads have been proposed wherein the cutting blades are mounted in longitudinal channels which are spaced about the surface of a cylindrical base member. One such prior design is illustrated in FIG. 1, wherein the blade B is mounted in a channel C and locked in place by means of a gib G which is biased by a set screws S. Mating corrugations are provided on the rear wall of the channel and the blade, so as to retain the blade in the channel. It will be apparent however, that if the set screws should loosen, both the gib and the blade could be released and fly out of the channel during the high speed rotation of the head, and damage to the equipment or injury to the operator could easily result.
Another prior shaper head design is illustrated in U.S. Pat. No. 5,163,490, wherein the locking gib is of wedge shape and biased against the blade by means of a set screw which extends through the gib in a generally radial direction. Here again, however, it is believed that in the event the set screw should loosen, the gib could drop away from its engagement with the blade such that only the separate retaining screws on the rear side of the blade would resist radial movement of the blade.
It is an object of the present invention to provide a shaper head of the described type which has an improved mounting structure for the blades and gibs, whereby the risk that a blade and gib could be released and fly out of the mounting channel during rotation of the head, is effectively avoided.